The present invention relates to munitions for weapons of small, medium and large caliber, and more particularly to an improved launcher with controlled separation of elements, for munitions of the type including a subcaliber bullet and a launcher, especially for hunting weapons.
In the weapons field, munitions are known which have a subcaliber projectile, combining a subprojectile and a launcher, the essential function of which is to propel the subprojectile at the desired velocity.
The launching techniques currently employed frequently use a launcher formed by two or more elements surrounding the subprojectile. The launcher elements, fitted together with contiguous planes by a locking system, may be made of metal alloys or of plastic. After firing, the aerodynamic forces exerted on the projectile on leaving the weapon cause the launcher elements to separate, from the front toward the rear, thus releasing the subprojectile. This separation of the launcher may be accelerated if the projectile is given a low rotational velocity resulting, for example, from the use of a weapon with a rifled tube. The launcher elements, after separation, each follow their own trajectory and fall at varying distances from the weapon.
For example, Patent No. FR-A-2,555,728 describes a munition for a hunting weapon including a fin-stabilized subcaliber projectile and including a dense-alloy tapered bullet and a plastic launcher.
However, this launching technique, with separation of the launcher from the front toward the rear, has many drawbacks. First of all, the ballistics of the launcher elements are not controlled and, consequently, may present a risk for persons who are near the firer. Moreover, the separation of the launcher elements may disturb the trajectory of the subprojectile, bearing on the latter during separation; this results in a greater ballistic dispersion of the subprojectile.
Patents FR-A-2,599,828 and FR-A-2,606,500 describe hunting bullets of the type including a subprojectile and a launcher made of several detachable elements, the characteristics of which are improved. Thus, Patent FR-A-2,599,828 describes a bullet having great stability of the trajectory, and therefore providing good firing accuracy, but becoming destabilized beyond a certain distance.
Patent FR-A-2,606,500 relates to a munition providing a high initial velocity and limiting the violence of the recoil shock, constituted by a subcaliber bullet and a launcher with the caliber of the weapon, including an open outer annular chamber which is separated from the propellent charge by a partition wall capable of breaking under the pressure of the gases generated by the combustion of the charge and is only delimited toward the outside by the wall of the cartridge case. This device has the advantage of reducing the recoil shock felt by the firer and, for the same pressure, of increasing the initial velocity of the projectile.
However, this outer annular expansion chamber does not make it possible to modify the direction of opening, from the front toward the rear, of the launcher elements during separation on leaving the weapon but, on the contrary, the risk of disturbing the trajectory of the bullet during separation of the launcher elements may be increased.
U.S. Pat. No. 5,182,419 describes a subprojectile combined with a one-piece launching sabot for a rifled-barrel military weapon mounted on an aircraft. The object of this device is to keep the launching sabot on a stable trajectory in order to prevent any impact with the aircraft's jet engines after separation of the subprojectile.